#!/usr/bin/env sh

# This is a wrapper script, that automatically selects or downloads Mill from Maven Central or GitHub release pages.
#
# This script determines the Mill version to use by trying these sources
#   - env-variable `MILL_VERSION`
#   - local file `.mill-version`
#   - local file `.config/mill-version`
#   - `mill-version` from YAML frontmatter of current buildfile
#   - if accessible, find the latest stable version available on Maven Central (https://repo1.maven.org/maven2)
#   - env-variable `DEFAULT_MILL_VERSION`
#
# If a version has the suffix '-native' a native binary will be used.
# If a version has the suffix '-jvm' an executable jar file will be used, requiring an already installed Java runtime.
# If no such suffix is found, the script will pick a default based on version and platform.
#
# Once a version was determined, it tries to use either
#    - a system-installed mill, if found and it's version matches
#    - an already downloaded version under ~/.cache/mill/download
#
# If no working mill version was found on the system,
# this script downloads a binary file from Maven Central or Github Pages (this is version dependent)
# into a cache location (~/.cache/mill/download).
#
# Mill Project URL: https://github.com/com-lihaoyi/mill
# Script Version: 1.0.6
#
# If you want to improve this script, please also contribute your changes back!
# This script was generated from: dist/scripts/src/mill.sh
#
# Licensed under the Apache License, Version 2.0

set -e

if [ -z "${DEFAULT_MILL_VERSION}" ] ; then
  DEFAULT_MILL_VERSION="1.0.6"
fi


if [ -z "${GITHUB_RELEASE_CDN}" ] ; then
  GITHUB_RELEASE_CDN=""
fi


MILL_REPO_URL="https://github.com/com-lihaoyi/mill"

if [ -z "${CURL_CMD}" ] ; then
  CURL_CMD=curl
fi

# Explicit commandline argument takes precedence over all other methods
if [ "$1" = "--mill-version" ] ; then
    echo "The --mill-version option is no longer supported." 1>&2
fi

MILL_BUILD_SCRIPT=""

if [ -f "build.mill" ] ; then
  MILL_BUILD_SCRIPT="build.mill"
elif [ -f "build.mill.scala" ] ; then
  MILL_BUILD_SCRIPT="build.mill.scala"
elif [ -f "build.sc" ] ; then
  MILL_BUILD_SCRIPT="build.sc"
fi

# Please note, that if a MILL_VERSION is already set in the environment,
# We reuse it's value and skip searching for a value.

# If not already set, read .mill-version file
if [ -z "${MILL_VERSION}" ] ; then
  if [ -f ".mill-version" ] ; then
    MILL_VERSION="$(tr '\r' '\n' < .mill-version | head -n 1 2> /dev/null)"
  elif [ -f ".config/mill-version" ] ; then
    MILL_VERSION="$(tr '\r' '\n' < .config/mill-version | head -n 1 2> /dev/null)"
  elif [ -n "${MILL_BUILD_SCRIPT}" ] ; then
    # `s/.*://`:
    #   This is a greedy match that removes everything from the beginning of the line up to (and including) the last
    #   colon (:). This effectively isolates the value part of the declaration.
    #
    #  `s/#.*//`:
    #    This removes any comments at the end of the line.
    #
    #  `s/['\"]//g`:
    #    This removes all single and double quotes from the string, wherever they appear (g is for "global").
    #
    #  `s/^[[:space:]]*//; s/[[:space:]]*$//`:
    #    These two expressions trim any leading or trailing whitespace ([[:space:]] matches spaces and tabs).
    MILL_VERSION="$(grep -E "//\|.*mill-version" "${MILL_BUILD_SCRIPT}" | sed -E "s/.*://; s/#.*//; s/['\"]//g; s/^[[:space:]]*//; s/[[:space:]]*$//")"
  fi
fi

MILL_USER_CACHE_DIR="${XDG_CACHE_HOME:-${HOME}/.cache}/mill"

if [ -z "${MILL_DOWNLOAD_PATH}" ] ; then
  MILL_DOWNLOAD_PATH="${MILL_USER_CACHE_DIR}/download"
fi

# If not already set, try to fetch newest from Github
if [ -z "${MILL_VERSION}" ] ; then
  # TODO: try to load latest version from release page
  echo "No mill version specified." 1>&2
  echo "You should provide a version via a '//| mill-version: ' comment or a '.mill-version' file." 1>&2

  mkdir -p "${MILL_DOWNLOAD_PATH}"
  LANG=C touch -d '1 hour ago' "${MILL_DOWNLOAD_PATH}/.expire_latest" 2>/dev/null || (
    # we might be on OSX or BSD which don't have -d option for touch
    # but probably a -A [-][[hh]mm]SS
    touch "${MILL_DOWNLOAD_PATH}/.expire_latest"; touch -A -010000 "${MILL_DOWNLOAD_PATH}/.expire_latest"
  ) || (
    # in case we still failed, we retry the first touch command with the intention
    # to show the (previously suppressed) error message
    LANG=C touch -d '1 hour ago' "${MILL_DOWNLOAD_PATH}/.expire_latest"
  )

  # POSIX shell variant of bash's -nt operator, see https://unix.stackexchange.com/a/449744/6993
  # if [ "${MILL_DOWNLOAD_PATH}/.latest" -nt "${MILL_DOWNLOAD_PATH}/.expire_latest" ] ; then
  if [ -n "$(find -L "${MILL_DOWNLOAD_PATH}/.latest" -prune -newer "${MILL_DOWNLOAD_PATH}/.expire_latest")" ]; then
    # we know a current latest version
    MILL_VERSION=$(head -n 1 "${MILL_DOWNLOAD_PATH}"/.latest 2> /dev/null)
  fi

  if [ -z "${MILL_VERSION}" ] ; then
    # we don't know a current latest version
    echo "Retrieving latest mill version ..." 1>&2
    LANG=C ${CURL_CMD} -s -i -f -I ${MILL_REPO_URL}/releases/latest 2> /dev/null  | grep --ignore-case Location: | sed s'/^.*tag\///' | tr -d '\r\n' > "${MILL_DOWNLOAD_PATH}/.latest"
    MILL_VERSION=$(head -n 1 "${MILL_DOWNLOAD_PATH}"/.latest 2> /dev/null)
  fi

  if [ -z "${MILL_VERSION}" ] ; then
    # Last resort
    MILL_VERSION="${DEFAULT_MILL_VERSION}"
    echo "Falling back to hardcoded mill version ${MILL_VERSION}" 1>&2
  else
    echo "Using mill version ${MILL_VERSION}" 1>&2
  fi
fi

MILL_NATIVE_SUFFIX="-native"
MILL_JVM_SUFFIX="-jvm"
FULL_MILL_VERSION=$MILL_VERSION
ARTIFACT_SUFFIX=""
set_artifact_suffix(){
  if [ "$(expr substr $(uname -s) 1 5 2>/dev/null)" = "Linux" ]; then
    if [ "$(uname -m)" = "aarch64" ]; then
      ARTIFACT_SUFFIX="-native-linux-aarch64"
    else
      ARTIFACT_SUFFIX="-native-linux-amd64"
    fi
  elif [ "$(uname)" = "Darwin" ]; then
    if [ "$(uname -m)" = "arm64" ]; then
      ARTIFACT_SUFFIX="-native-mac-aarch64"
    else
      ARTIFACT_SUFFIX="-native-mac-amd64"
    fi
  else
     echo "This native mill launcher supports only Linux and macOS." 1>&2
     exit 1
  fi
}

case "$MILL_VERSION" in
    *"$MILL_NATIVE_SUFFIX")
  MILL_VERSION=${MILL_VERSION%"$MILL_NATIVE_SUFFIX"}
  set_artifact_suffix
  ;;

    *"$MILL_JVM_SUFFIX")
    MILL_VERSION=${MILL_VERSION%"$MILL_JVM_SUFFIX"}
  ;;

    *)
  case "$MILL_VERSION" in
    0.1.*) ;;
    0.2.*) ;;
    0.3.*) ;;
    0.4.*) ;;
    0.5.*) ;;
    0.6.*) ;;
    0.7.*) ;;
    0.8.*) ;;
    0.9.*) ;;
    0.10.*) ;;
    0.11.*) ;;
    0.12.*) ;;
    *)
      set_artifact_suffix
  esac
  ;;
esac

MILL="${MILL_DOWNLOAD_PATH}/$MILL_VERSION$ARTIFACT_SUFFIX"

try_to_use_system_mill() {
  if [ "$(uname)" != "Linux" ]; then
    return 0
  fi

  MILL_IN_PATH="$(command -v mill || true)"

  if [ -z "${MILL_IN_PATH}" ]; then
    return 0
  fi

  SYSTEM_MILL_FIRST_TWO_BYTES=$(head --bytes=2 "${MILL_IN_PATH}")
  if [ "${SYSTEM_MILL_FIRST_TWO_BYTES}" = "#!" ]; then
	  # MILL_IN_PATH is (very likely) a shell script and not the mill
	  # executable, ignore it.
	  return 0
  fi

  SYSTEM_MILL_PATH=$(readlink -e "${MILL_IN_PATH}")
  SYSTEM_MILL_SIZE=$(stat --format=%s "${SYSTEM_MILL_PATH}")
  SYSTEM_MILL_MTIME=$(stat --format=%y "${SYSTEM_MILL_PATH}")

  if [ ! -d "${MILL_USER_CACHE_DIR}" ]; then
    mkdir -p "${MILL_USER_CACHE_DIR}"
  fi

  SYSTEM_MILL_INFO_FILE="${MILL_USER_CACHE_DIR}/system-mill-info"
  if [ -f "${SYSTEM_MILL_INFO_FILE}" ]; then
    parseSystemMillInfo() {
        LINE_NUMBER="${1}"
        # Select the line number of the SYSTEM_MILL_INFO_FILE, cut the
        # variable definition in that line in two halves and return
        # the value, and finally remove the quotes.
        sed -n "${LINE_NUMBER}p" "${SYSTEM_MILL_INFO_FILE}" |\
            cut -d= -f2 |\
            sed 's/"\(.*\)"/\1/'
    }

    CACHED_SYSTEM_MILL_PATH=$(parseSystemMillInfo 1)
    CACHED_SYSTEM_MILL_VERSION=$(parseSystemMillInfo 2)
    CACHED_SYSTEM_MILL_SIZE=$(parseSystemMillInfo 3)
    CACHED_SYSTEM_MILL_MTIME=$(parseSystemMillInfo 4)

    if [ "${SYSTEM_MILL_PATH}" = "${CACHED_SYSTEM_MILL_PATH}" ] \
           && [ "${SYSTEM_MILL_SIZE}" = "${CACHED_SYSTEM_MILL_SIZE}" ] \
           && [ "${SYSTEM_MILL_MTIME}" = "${CACHED_SYSTEM_MILL_MTIME}" ]; then
      if [ "${CACHED_SYSTEM_MILL_VERSION}" = "${MILL_VERSION}" ]; then
          MILL="${SYSTEM_MILL_PATH}"
          return 0
      else
          return 0
      fi
    fi
  fi

  SYSTEM_MILL_VERSION=$(${SYSTEM_MILL_PATH} --version | head -n1 | sed -n 's/^Mill.*version \(.*\)/\1/p')

  cat <<EOF > "${SYSTEM_MILL_INFO_FILE}"
CACHED_SYSTEM_MILL_PATH="${SYSTEM_MILL_PATH}"
CACHED_SYSTEM_MILL_VERSION="${SYSTEM_MILL_VERSION}"
CACHED_SYSTEM_MILL_SIZE="${SYSTEM_MILL_SIZE}"
CACHED_SYSTEM_MILL_MTIME="${SYSTEM_MILL_MTIME}"
EOF

  if [ "${SYSTEM_MILL_VERSION}" = "${MILL_VERSION}" ]; then
    MILL="${SYSTEM_MILL_PATH}"
  fi
}
try_to_use_system_mill

# If not already downloaded, download it
if [ ! -s "${MILL}" ] || [ "$MILL_TEST_DRY_RUN_LAUNCHER_SCRIPT" = "1" ] ; then
  case $MILL_VERSION in
    0.0.* | 0.1.* | 0.2.* | 0.3.* | 0.4.* )
      DOWNLOAD_SUFFIX=""
      DOWNLOAD_FROM_MAVEN=0
      ;;
    0.5.* | 0.6.* | 0.7.* | 0.8.* | 0.9.* | 0.10.* | 0.11.0-M* )
      DOWNLOAD_SUFFIX="-assembly"
      DOWNLOAD_FROM_MAVEN=0
      ;;
    *)
      DOWNLOAD_SUFFIX="-assembly"
      DOWNLOAD_FROM_MAVEN=1
      ;;
  esac
  case $MILL_VERSION in
    0.12.0 | 0.12.1 | 0.12.2 | 0.12.3 | 0.12.4 | 0.12.5 | 0.12.6 | 0.12.7 | 0.12.8 | 0.12.9 | 0.12.10 | 0.12.11 )
      DOWNLOAD_EXT="jar"
      ;;
    0.12.* )
      DOWNLOAD_EXT="exe"
      ;;
    0.* )
      DOWNLOAD_EXT="jar"
      ;;
    *)
      DOWNLOAD_EXT="exe"
      ;;
  esac

  DOWNLOAD_FILE=$(mktemp mill.XXXXXX)
  if [ "$DOWNLOAD_FROM_MAVEN" = "1" ] ; then
    DOWNLOAD_URL="https://repo1.maven.org/maven2/com/lihaoyi/mill-dist${ARTIFACT_SUFFIX}/${MILL_VERSION}/mill-dist${ARTIFACT_SUFFIX}-${MILL_VERSION}.${DOWNLOAD_EXT}"
  else
    MILL_VERSION_TAG=$(echo "$MILL_VERSION" | sed -E 's/([^-]+)(-M[0-9]+)?(-.*)?/\1\2/')
    DOWNLOAD_URL="${GITHUB_RELEASE_CDN}${MILL_REPO_URL}/releases/download/${MILL_VERSION_TAG}/${MILL_VERSION}${DOWNLOAD_SUFFIX}"
    unset MILL_VERSION_TAG
  fi

  if [ "$MILL_TEST_DRY_RUN_LAUNCHER_SCRIPT" = "1" ] ; then
    echo $DOWNLOAD_URL
    echo $MILL
    exit 0
  fi
  # TODO: handle command not found
  echo "Downloading mill ${MILL_VERSION} from ${DOWNLOAD_URL} ..." 1>&2
  ${CURL_CMD} -f -L -o "${DOWNLOAD_FILE}" "${DOWNLOAD_URL}"
  chmod +x "${DOWNLOAD_FILE}"
  mkdir -p "${MILL_DOWNLOAD_PATH}"
  mv "${DOWNLOAD_FILE}" "${MILL}"

  unset DOWNLOAD_FILE
  unset DOWNLOAD_SUFFIX
fi

if [ -z "$MILL_MAIN_CLI" ] ; then
  MILL_MAIN_CLI="${0}"
fi

MILL_FIRST_ARG=""
if [ "$1" = "--bsp" ] || [ "${1#"-i"}" != "$1" ] || [ "$1" = "--interactive" ] || [ "$1" = "--no-server" ] || [ "$1" = "--no-daemon" ] || [ "$1" = "--repl" ] || [ "$1" = "--help" ] ; then
  # Need to preserve the first position of those listed options
  MILL_FIRST_ARG=$1
  shift
fi

unset MILL_DOWNLOAD_PATH
unset MILL_OLD_DOWNLOAD_PATH
unset OLD_MILL
unset MILL_VERSION
unset MILL_REPO_URL

# -D mill.main.cli is for compatibility with Mill 0.10.9 - 0.13.0-M2
# We don't quote MILL_FIRST_ARG on purpose, so we can expand the empty value without quotes
# shellcheck disable=SC2086
exec "${MILL}" $MILL_FIRST_ARG -D "mill.main.cli=${MILL_MAIN_CLI}" "$@"
